Decorative article



Patented Nov. 28, 1944 ;or to Monsanto Chemical Company, St. Louis,

Mo., a corporation of Delaware r j No Drawing. Application Mayra, 1940,

Serial No. 335,505 18 Claims. (01. 260-17) This invention relates to plastic compositions comprising polystyrene and cellulose ethers relatively immiscible therewith.

It is well-known that certain compositions comprising synthetic resins and/or other high molecular weight substances lend themselves cellulose, ethyl;cellulose, benzyltcellulosel and thelike, The cellulose ethers are-incorporated in the [polystyrene by any suitable means but, preferreadily to the manufacture of articles possessing a highly decorative appearance. It has been found that a number of the color effects available in certain natural materials, which are exceptionally pleasing to the eye, are also} desirable in saidmanufactured products. Among said color efiects, there are two, more. or less related and particularly desirable color effects,

which are to be found in natural pearls and opals. Unfortunately, the colors of pearls and opals have tended to be extremely difficult and expensive to reproduce. Generally, special materials and processes have been required toimpart these decorative effects to'the plastic compositions of industry.

One object of. this invention is to provide decorative articles comprising polystyrene and cellulose ethers relatively immiscible therewith.

Another object is to providecompositions comprising polystyrene and cellulose ethers relatively immiscible therewith, said compositions, possessing a lustrous, nacreous appearance resembling, for example, natural pearls and opals. 3

It is well-known to those skilled in the art that the addition, for example, of suitable fish scale materialto cellulose ester compositions, im-

parts to said compositions an appearance simulating that of natural pearls. However, this fish scale material is very expensive and special processing conditions are required to produce compositions possessing said pearly appearance. For example, nacreous articles comprising polystyrene have been found difficult to produce by incorporating fish scale material therein.

However, by the process of the present inven-- tion, it has been found possible, withoutthe necessity of special processing methods, to prepare decorative articles comprising polystyrene and possessing a decidedly attractive, nacreous and/or opalescent appearance. These highly valuable and unexpected results have been accomplished by incorporating celluloseethers in polystyrene.

The cellulose ethers that produce these decorative effects when incorporated in polystyrene are, the cellulose ethers of commerce and, are

characterizedby relative immiscibility with poly-- styrene. Illustrative of the cellulose ethersthat can be employed by this invention are methyl ably, by means of hot milling rolls under suitable milling conditions. A mixing period of substantially minutes at aroll temperature of substantiallyl r. to 320 F. has been found suitable, Thetwo. components can be mixed in all proportions and ,still produce articles possessing the previously describeddecorative appearance. However, in order to impart, to the article a strongly nacreous appearance, it is generally necessary that neither component be presentin excess of substantially by weight of the sum of the weights of the two components, Nevertheless, even whenone component is present in excess, of substantially 90% by Weight of the sum of the weights of the two components, the products are still very attractive and those containing as'little as 0.4 part by weight of one component for every parts by weightof the other component have been found tobe beautifully opalescent.

The following specific examples are illustra tive of the present invention but are not limitativeof the scope thereof. The parts are parts by weight.

Example 1 30 parts of commercial high viscosity ethyl cellulose, were incorporated in 100 parts of .polystyrene, of such a degree of polymerization that a 10% toluol solution of said polystyrene possessed aviscosity of substantially 200 centipoises at 25 C. After milling for substantially 20 minutes on the mixing rolls at a roll temperature of substantially the product was then suitably, comminuted and molded by aninjectionmolding process. .An exceedingly, striking, lustrous, nacreous appearance was imparted to the molded product. i

3 Example 2 30parts of commercial low viscosity ethyl cellulose were incorporated in 100parts of polystyrene similar. to that employed in Examplel. .Themethod of-incorporatingi the ethylcellulose in the polystyrene was similarto thatem ployeci in Example 1 and the product obtained possessed a similar appearance. j

The hereinbefore described specific examples of this invention have all illustratedthe preparation of articles possessing a nacreous appear ance by incorporating ethyl ethers of cellulose inpolystyrene. However, as previously indicated,- j

subject to wide variation. F10

Other methods of incorporating the-cellulose ethers in polystyrene may be employed by this invention and, furthermore 'zetheseanewaproducts f are not limited to compositionsrcomprisingmnly one cellulose ether relatively immiscible therewith, but, if desired, a mixture. of ..,said..-cellulose.

ethers may be incorporated in polystyreneto form decorative articles. The mixtures of the two components do not have to be moldedtobring 2.. out .thepearly appearance;- .thus, .calenderingand other finishing processes may be employed; Dyes, pigments,....fillers ...and other... modifiers may be added as desired.

. ...The present invention. is limitedsolelyby..the

claims,.attached hereto.

. .lWhat .Lclaim. is: p 7.

1. A decorative. article ;.-.-characterized. by... an opalescent appearance consisting.essentially in polystyrene and .alcelluloseether. relativelyim- .miscible'... .therewith,...physically intermixed lwith said polystyrene. while. .in 1a heatsoftened ..con-

dition toimpart toLthe article a-..na'creous...and .-...-:pearlescent. appearance.

2 A. composition. ofamatter';characterizedjby ,..an.. opalescent l-appear-ance consisting 01".. poly styrene. and a .cellulose/ ether. relatively. immiscible therewith,..physica11y.. intermixedwith said polystyrene .while: in a '-.heat-softened condition .e togive anacreous and pearlescentappearance to i i saidcomposition. Y

. 3.. A--decorative aarticle.characterized by. an

a .opalescent appearance. consisting .--,essenti'ally. in

polystyrene and acelluloseether.relatively. immiscible. therewith. wherein neither. component of said article is present in excess. of --substantially .90 percent byhweight of. the sum o f.--.the

weights of the two components, said-cellulose ether being physically intermixed with said poly- .styrene while in a heat softened. condition to "f'zimp'art to the 'articl'e a' nacreous and 'pearlescent "appearance.

4. A decorative-"article characterized by an .opalescent appearance consisting-"essentially in polysyreneand anethyl cellulose relatively immiscible therewith,:-physically intermixed with said polystyrenewhile in a "heatsoftened condi. tion to-impart to-.the article anacreous and -'pearlescentgappearance. i

Anacreous-pomposition of *matterconsistingessentiall'y in polystyrene-.andan ethyl cellu lose relatively immiscible" therewithphysically intermixed withssaidpolystyrene while in a heat ..sotened;.condition to..i,mpart anacreous and .pe'arlescent appearance to. the composition.

1. 6.... A decorative .article'. characterized by. an

;...opalescent appearance consisting essentially in .....polystyrene. and amethylcellulose relatively im- .Ini'S'c'ible'ltherewith, physicallyv intermixed with said polystyrene .while in a heat .lsoftenedcon- -.dition to impart tolthe article a nacreous and pearlescent appearance.

7. Anacreous composition of.matter.consist- .-ing.essentially inpolystyrene andga methyl cel- Qlulose relatively. immiscible therewith physically intermixed with said polystyrene while in a'heatsoftened condition to impart a nacreous and pearlescent appearance to the composition.

8. A decorative article characterized by an opalescent appearance consisting essentially in 5 polystyrene and a benzyl cellulose relatively immiscible therewith, physically intermixed with said polystyrene while in a-e heatfisoftened con- -dit-ion to imp'art tothe article 'a' nacreous and pearlescent appearance.

ingessentially in polystyrene and a benzyl cellulose relatively immiscible therewith, physical- "lyrintermixediiwitlr said polystyrene while in a eat softe'ned': condition to impart a nacreous and pearlescent appearanceto the composition.

. 10.. Aprocess of preparing a decorative artitecle'zcharacterized by an opalescent appearance which comprises heat softening and physically 'intermixing with polystyrene while in a heat- "1: .-:softened condition a cellulose etherrelatively immiscible therewith to impart. an opalescent; appearance to said article, and then. injection mold- .a: ing. .the-.-resulting..composition; into 2.the. desired -".--shape. 4' .11. .Therprocess ofipreparinga decorative-arti- ..:..-cle characterized by. an 1 opalescent. appearance which ,comprisessheat softening. and physically 1 1" intermixingwith-- polystyrene .while in a":'heat- ..-.-softened.-condition a; celluloseether relatively 5 immiscible" therewith to impart; an' opalescent appearancetosaid article, andwthen. forming the :1 resulting composition under :pressure and 1ele- =-vatedw temperaturefinto: the desired shape, thus :"producing. anarticle havinga; nacreous: an'cltpear- .r;lescent appearance. v i l 1 12.. .The process of preparing a'decora'tiverarti- -rucle characterized-by an-;opalescent appearance -.-which compriseswheat softening and physically :.intermixing "with 1 DOIYStYIBI'lC-ZiiWhlle. in a" heatsoftened condition a cellulose fetherrelatively immiscible therewith to impart an :opalescent appearance to. :said'ia rticle; wherein" neither com- :nponent oflsaid article is present in'. excess ofsubizstantially QOpercent -by-Weight of the sum of a'vthe weights of' the two components and then "*"forming'the resulting composition under-presr i sure and elevated temperature into the desired shape, thus producing an 'articlehaving' a nacre- :-ous. appearance. 3

l I3.' The process of preparing a decorative artiw cle characterize'dwby an =opalescent appearance ""whichcomprises incorporating in polystyrene while in a heat-softened condition essentially 5"? only an" ethyl cellulosa relatively immiscible therewith to: impart ar'r'o'palescent appearance to said-*articlaand then forming the resulting composition under heat and pressure into the desired shape. 1

14".The process of preparing a'decorativea'rti- *clecharacterized'by'an opalescent appearance which comprises incorporating in" polystyrene.

.while in a. heat-softened condition essentially ...only a benzylwcellulose relatively immiscible therewith. to. impart. an .opaIeScent..appearance to said article, and then forming. the resulting 9. A nacreous composition of matter consist- 'cle characterized by an opalescent appearance which comprises incorporating .in polystyrene composition under heat and pressure into the desired shape. y

16. A composition of matter comprising polystyrene and a cellulose ether immiscible therer with physically intermixed with said polystyrene while in a heat-softened condition to give a nacreous and pearlescent appearance to said composition.

1'7. Process of producing a composition of matter having a nacreous appearance, which comprises physically intermixing while in a. heat softened condition polystyrene and a, cellulose ether relatively immiscible therewith to give a nacreous appearance to the resulting composition.

18. Process of producing an article having a nacreous appearance which comprises heat softening and physically intermixing while in a heat softened condition polystyrene and a cellulose ether relatively immiscible therewith to give a nacreous'appearance to the resulting composition, then comminuting the resulting composition and injection molding said comminuted composition to produce said article.

RALPH F. HAYES. 

